Synthesis of purified, partially esterified polyol polyester fatty acid compositions

ABSTRACT

This invention relates to processes for the production of purified, partially esterified polyol fatty acid polyesters and the compositions derived from those processes. The purified, partially esterified polyol fatty acid polyesters of the present invention are particularly well suited for use in a variety of food, beverage, pharmaceutical, and cosmetic applications and comprise less than about 5% polyol; less than about 5 ppm of residual solvent; less than about 700 ppm of lower alky esters; less than about 5% of a soap and free fatty acid mixture; less than about 3% of ash; and have an acid value of less than about 6.

BRIEF DESCRIPTION OF THE INVENTION

This invention relates to processes for the production of purified,partially esterified polyol fatty acid polyesters. More particularly,this invention relates to processes for preparing purified, partiallyesterified polyol fatty acid polyesters that include aqueous and alcoholbased purification processes, and the products made according to thoseprocesses.

BACKGROUND OF THE INVENTION

As a result of their physical properties, partially esterified polyolfatty acid polyesters are commonly used as emulsifiers and surfactantsin various food, beverage, and cosmetic compositions. There exists inthe art various techniques for the synthesis of these partiallyesterified polyol fatty acid polyesters.

U.S. Pat. No. 4,927,920, to Wagner et al. discloses a process for theproduction of sugar esters with a degree of substitution of less thantwo by reacting a sugar, an organic solvent, and a sugar ester with adegree of substitution greater than two. The recovery of the solventoccurs at a temperature below the distillation temperature of theorganic solvent.

U.S. Pat. No. 4,996,309, to Matsumoto et al. discloses a process forpreparing sucrose fatty acid esters by reacting sucrose and fatty acidalkyl esters in the presence of a catalyst. The resulting sucrose estersare collected and washed with an acid solution.

Although conventional processes for the manufacture of partiallyesterified polyol fatty acid polyesters have known utilities, theysuffer from several deficiencies, most notable of which are poorreaction control and the need for expensive, complex and continuouspurification techniques. Additionally, these known processes are unableto accurately predict and consistently control the exact composition ofthe finished product without the use of complex sampling and controlmodification procedures throughout the reaction.

These known processes also suffer from an inability to accuratelycontrol the average degree of esterification in the final partiallyesterified polyol polyester compositions. Moreover, the partiallyesterified polyol polyester compositions produced from these knownsynthesis techniques typically contain unacceptable levels ofimpurities, such as solvent, polyol, lower alkyl esters, ash, soap, freefatty acids, and other unwanted reaction byproducts.

These limitations have heretofore constrained the industrialapplicability and cost effective commercialization of these compounds invarious food, beverage, pharmaceutical, and cosmetic applications.

Accordingly, it is an object of the present invention to provideprocesses for the synthesis of purified, partially esterified polyolpolyesters that allow for the production of polyol polyesters with thedegree of purity necessary for widespread incorporation into a varietyof industrial and commercial applications. It is another object of thepresent invention to provide purified, partially esterified polyolpolyester compositions with a degree of purity sufficient to be used ina variety of industrial and commercial applications. It is yet anotherobject of the present invention to provide processes for the productionof purified polyol polyesters that are efficient, cost effective, andrequire less purification than those now known and employed in the art.

SUMMARY OF THE INVENTION

This invention relates to processes for the production of purified,partially esterified polyol fatty acid polyesters and the compositionsmade from those processes. More particularly, this invention relates toprocesses for preparing partially esterified polyol fatty acidpolyesters that include aqueous and alcohol based purificationprocesses. The purified, partially esterified polyol fatty acidpolyesters of the present invention are particularly well suited for usein a variety of food, beverage, pharmaceutical, and cosmeticapplications, and comprise less than about 5% polyol; less than about 5ppm of residual solvent; less than about 700 ppm of lower alky esters;less than about 5% of a soap and free fatty acid mixture; less thanabout 3% of ash; and an acid value of less than about 6. In a preferredembodiment of the present invention the purified partially esterifiedpolyol polyester is a purified partially esterified sucrose polyestercomprising less than about 4% sucrose; less than about 3 ppm of residualsolvent; less than about 700 ppm of lower alky esters; less than about5% of a soap and free fatty acid mixture; less than about 3% of ash; andan acid value of less than about 4.

DETAILED DESCRIPTION OF THE INVENTION

The present invention encompasses esterification processes for theproduction of partially esterified polyol fatty acid polyesters, inparticular highly purified, partially esterified polyol fatty acidpolyesters. The present invention will now be described in detail withreference to specific embodiments.

A. Definitions

Various publications and patents are referenced throughout thisdisclosure. All references cited herein are hereby incorporated byreference. Unless otherwise indicated, all percentages and ratios arecalculated by weight. All percentages and ratios are calculated based onthe total dry composition unless otherwise indicated.

All component or composition levels are in reference to the active levelof that component or composition, and are exclusive of impurities, forexample, residual solvents or by-products, which may be present incommercially available sources.

Referred to herein are trade names for components including variousingredients utilized in the present invention. The inventors herein donot intend to be limited by materials under a certain trade name.Equivalent materials (e.g., those obtained from a different source undera different name or catalog number) to those referenced by trade namemay be substituted and utilized in the compositions, kits, and methodsherein.

As used herein, and unless otherwise indicated, the use of a numericrange to indicate the value of a given variable is not intended to belimited to just discrete points within that stated range. One ofordinary skill in the art will appreciate that the use of a numericrange to indicate the value of a variable is meant to include not justthe values bounding the stated range, but also all values and sub-rangescontained therein. By way of example, consider variable X that isdisclosed as having a value in the range of A to B. One of ordinaryskill in the art will understand that variable X is meant to include allinteger and non-integer values bounded by the stated range of A to B.Moreover, one of ordinary skill in the art will appreciate that thevalue of the variable also includes all combinations and/or permutationsof sub-ranges bounded by the integer and non-integer values within andincluding A and B.

As used herein, the term “partially esterified polyol polyester” isintended to include those esters of the polyol having a degree ofesterification in excess of the degree of esterification of the polyol,but less than the degree of esterification of the highly esterifiedpolyol fatty acid polyester. As used herein, the term “degree ofesterification” refers to the average percentage of hydroxyl groups of apolyol composition that have been esterified.

In one embodiment of the present invention the polyol is sucrose havingeight hydroxyl groups. The partially esterified sucrose polyesterpreferably has a degree of esterification of less than about 50%,preferably less than about 40%, more preferably less than about 30%,most preferably less than about 15%. As used herein the degree ofesterification calculation does not include non-esterified polyolcompounds that may be present.

In the description of the invention various embodiments and/orindividual features are disclosed. As will be apparent to the ordinarilyskilled practitioner, all combinations of such embodiments and featuresare possible and can result in preferred executions of the presentinvention.

B. Processes for Synthesizing Purified, Partially Esterified Polyolpolyester Fatty Acid Compositions

In general, the processes for the preparation of purified, partiallyesterified polyol fatty acid polyesters of the present inventioncomprise the steps of forming an initial reaction product from aninitial reaction mixture; forming a secondary reaction product byreacting the initial reaction product in the presence of a secondaryreaction mixture; optionally neutralizing remaining catalyst; optionallyforming a tertiary reaction product to recover reaction components(e.g., solvent) via such processes as evaporation; and purifying thetertiary reaction product and removing any isolated impurities and/orunreacted components.

i) Initial Reaction Product

An initial reaction product is formed by reacting an initial reactionmixture in an inert atmosphere, for a period of time in the range offrom about 30 minutes to about 6 hours, and at a temperature in therange of from about 80° C. to about 140° C.

The initial reaction mixture comprises a polyol portion, a highlyesterified polyol fatty acid polyester, a solvent, and a catalyst.Preferably, the molar ratio of the catalyst to the highly esterifiedpolyol fatty acid polyester is in the range of from about 0.01:1 toabout 10:1, more preferably in the range of from about 0.1:1 to about5:1, yet more preferably from about 0.25:1 to about 1:1, most preferablyin the range of from about 0.4:1 to about 0.6:1. Preferably the weightratio of the solvent to the combined weight of the polyol portion, thehighly esterified polyol ester fatty acid, and the catalyst is in therange of from about 1:1 to about 20:1, more preferably in the range offrom about 3:1 to about 10:1, most preferably in the range of from about4:1 to about 6:1. The molar ratio of polyol to highly esterified polyolpolyester is in the range of from about 0.1:1 to about 40:1, preferablyin the range of from about 1:1 to about 40:1, more preferably in therange of from about 5:1 to about 20:1, even more preferably in the rangeof from about 12:1 to about 18:1.

In one embodiment of the present invention the polyol is sucrose and thehighly esterified polyol fatty acid polyester is sucrose polyester witha degree of esterification of about 95%.

As used herein, the term “polyol” is intended to include any aliphaticor aromatic compound containing at least two free hydroxyl groups. Inpracticing the processes disclosed herein, the selection of a suitablepolyol is simply a matter of choice. For example, suitable polyols maybe selected from the following classes: saturated and unsaturatedstraight and branched chain linear aliphatic; saturated and unsaturatedcyclic aliphatic, including heterocyclic aliphatic; or mononuclear orpolynuclear aromatics, including heterocyclic aromatics. Carbohydratesand glycols are exemplary polyols. Especially preferred glycols includeglycerin. Monosaccharides suitable for use herein include, for example,mannose, galactose, arabinose, xylose, ribose, apiose, rhamnose,psicose, fructose, sorbose, tagitose, ribulose, xylulose, anderythrulose. Oligosaccharides suitable for use herein include, forexample, maltose, kojibiose, nigerose, cellobiose, lactose, melibiose,gentiobiose, turanose, rutinose, trehalose, sucrose and raffinose.Polysaccharides suitable for use herein include, for example, amylose,glycogen, cellulose, chitin, inulin, agarose, zylans, mannan andgalactans. Although sugar alcohols are not carbohydrates in a strictsense, the naturally occurring sugar alcohols are so closely related tothe carbohydrates that they are also preferred for use herein. The sugaralcohols most widely distributed in nature and suitable for use hereinare sorbitol, mannitol and galactitol.

Particular classes of materials suitable for use herein includemonosaccharides, disaccharides and sugar alcohols. Other classes ofmaterials include sugar ethers and alkoxylated polyols, such aspolyethoxy glycerol.

In one embodiment of the present invention the polyol has on average atleast four, preferably at least about 5, more preferably about 8hydroxyl groups capable of being esterified per polyol molecule.

Suitable esterified epoxide-extended polyols include esterifiedpropoxylated glycerols prepared by reacting a propoxylated glycerolhaving from 2 to 100 oxypropylene units per glycerol with C₁₀-C₂₄ fattyacids or with C₁₀-C₂₄ fatty acid esters, as described in U.S. Pat. Nos.4,983,329 and 5,175,323, respectively, and esterified propoxylatedglycerols prepared by reacting an epoxide and a triglyceride with analiphatic polyalcohol, as described in U.S. Pat. No. 5,304,665 or withan alkali metal or alkaline earth salt of an aliphatic alcohol, asdescribed in U.S. Pat. No. 5,399,728. Other polyols include acylatedpropylene oxide-extended glycerols having a propoxylation index of aboveabout 2, preferably in the range of from about 2 to about 8, morepreferably about 5 or above, wherein the acyl groups are C₈-C₂₄,preferably C₁₄-C₁₈, compounds, as described in U.S. Pat. Nos. 5,603,978and 5,641,534 and fatty acid-esterified propoxylated glycerols, asdescribed in U.S. Pat. Nos. 5,589,217 and 5,597,605.

Other suitable esterified epoxide-extended polyols include esterifiedalkoxylated polysaccharides. Preferred esterified alkoxylatedpolysaccharides are esterified alkoxylated polysaccharides containinganhydromonosaccharide units, more preferred are esterified propoxylatedpolysaccharides containing anhydromonosaccharide units, as described inU.S. Pat. No. 5,273,772.

The polyol has a degree of esterification less than the degree ofesterification of both the partially esterified polyol polyester and thehighly esterified polyol fatty acid polyester. The first polyol portionmay be a single type or class of polyol (e.g., sucrose) or mayalternatively be a blend of two or more types or classes of polyols(e.g., a sugar alcohols, such as sorbitol; monosaccharides, such asfructose; and oligosaccharides, such as maltose).

As used herein, the term “highly esterified polyol fatty acid polyester”is intended to include those esters of a polyol with a degree ofesterification in excess of the degree of esterification of both thepolyol and the partially esterified polyol polyester. In one embodimentof the invention the highly esterified polyol polyester has a degree ofesterification of at least about 70%, while in yet another embodimentthe highly esterified polyol polyester has a degree of esterification ofat least about 90%, preferably at least about 95%.

A variety of processes are known in the art for the synthesis of highlyesterified polyol fatty acid polyesters that are suitable for use in theprocesses of the present invention. Examples of such processes aredetailed in U.S. Pat. No. 3,963,699, to Rizzi et al., disclosing asolvent-free transesterification process in which a mixture of a polyol(such as sucrose), a fatty acid lower alkyl ester (such as a fatty acidmethyl ester), an alkali metal fatty acid soap, and a basic catalyst isheated to form a homogenous melt. Excess fatty acid lower alkyl ester isadded to the melt to form the higher polyol fatty acid polyesters. Thepolyesters are then separated from the reaction mixture by any of theroutinely used separation procedures; distillation or solvent extractionare preferred. Additional suitable processes include U.S. Pat. No.4,517,360, to Volpenhein et al.; U.S. Pat. No. 5,422,131, to Elsen etal.; U.S. Pat. No. 5,648,483, to Granberg et al.; U.S. Pat. No.5,767,257, to Schafermeyer et al., and U.S. Pat. No. 6,261,628, to Howieet al., each of which is herein incorporated by reference.

In one embodiment of the present invention, the highly esterified polyolfatty acid polyesters are sucrose fatty acid polyesters, having anaverage of at least 4 fatty acid groups per molecule. In anotherembodiment of the invention, the highly polyol fatty acid polyester issucrose fatty acid polyester having an average of at least 5 fatty acidgroups per molecule, while in another embodiment the sucrose fatty acidpolyesters have an average of from about 5 to about 8 fatty acid groupsper molecule. In yet another embodiment, the polyol polyester is asucrose polyester wherein at least about 75% of the sucrose polyestercomprises octaester.

The fatty acid chains of the highly esterified polyol fatty acidpolyesters may be branched, linear, saturated, unsaturated,hydrogenated, unhydrogenated, or mixtures thereof. The fatty acid chainsof the fatty acid esters have from about 6 to about 30 total carbonatoms. As used herein, reference to a fatty acid compound having fattyacid chains of a particular length is intended to mean that a majorityof the fatty acid chains, i.e., greater than 50 mol % of the fatty acidchains, have the stated length. In a more specific embodiment, the fattyacid compounds have greater than about 60 mol %, and more specificallygreater than about 75 mol %, of fatty acid chains of the stated length.As used herein “fatty acid ester” is intended to include fatty acidesters in which the fatty acid chains have a total of from about 2 toabout 28, typically from about 8 to about 22, carbon atoms. The fattyacid esters may be branched, unbranched, saturated, unsaturated,hydrogenated, unhydrogenated, or mixtures thereof.

In one embodiment of the present invention, the fatty acid chains of thepolyester may be branched or linear and may be formed from fatty acidesters having fatty acid chains of from about 8 to about 26 total carbonatoms. In yet another embodiment, the fatty acid chains of the fattyacid ester have from about 16 to about 22 total carbon atoms.

Other suitable polyol fatty acid polyesters are esterified linkedalkoxylated glycerins, including those comprising polyether glycollinking segments, as described in U.S. Pat. No. 5,374,446 and thosecomprising polycarboxylate linking segments, as described in U.S. Pat.Nos. 5,427,815 and 5,516,544.

Additional suitable polyol fatty acid polyesters are esterifiedepoxide-extended polyols of the general formulaP(OH)_(A+C)(EPO)_(N)(FE)_(B) wherein P(OH) is a polyol, A is from 2 toabout 8 primary hydroxyls, C is from about 0 to about 8 total secondaryand tertiary hydroxyls, A+C is from about 3 to about 8, EPO is a C₃-C₆epoxide, N is a minimum epoxylation index average number, FE is a fattyacid acyl moiety and B is an average number in the range of greater than2 and no greater than A+C, as described in U.S. Pat. No. 4,861,613. Theminimum epoxylation index average number has a value generally equal toor greater than A and is a number sufficient so that greater than 95% ofthe primary hydroxyls of the polyol are converted to secondary ortertiary hydroxyls. Preferably the fatty acid acyl moiety has a C₇-C₂₃alkyl chain.

The highly esterified polyol fatty acid polyester may be comprised of asingle type or class of polyol polyester (e.g., sucrose) or mayalternatively be a blend of two or more types or classes of polyolpolyesters (e.g., a sugar alcohols, such as sorbitol; monosaccharides,such as fructose; and oligosaccharides, such as maltose). The polyolbackbones of the highly esterified polyol fatty acid polyesters (e.g.,sucrose in a highly esterified sucrose fatty acid polyester) may be thesame backbone as the polyol, or may optionally be comprised of two ormore different polyol backbones.

In one embodiment of the present invention the polyol is sucrose and thehighly esterified polyol fatty acid polyester is predominantly (i.e., inexcess of about 95%, preferably in excess of about 98%, more preferablyin excess of about 99%) comprised of sucrose fatty acid polyester. Inanother embodiment the polyol is glucose and the highly esterifiedpolyol fatty acid polyester is sucrose fatty acid polyester. In yetanother embodiment, the polyol is sucrose and the highly esterifiedfatty acid polyester is comprised of sucrose fatty acid polyester and ahighly esterified epoxide-extended polyol polyester.

Suitable basic compounds to be used as basic reaction catalysts includealkali metals such as sodium, lithium and potassium; alloys of two ormore alkali metals such as sodium-lithium and sodium-potassium alloys;alkali metal hydrides, such as sodium, lithium and potassium hydride;alkali metal lower (C₁-C₄) alkyls such as butyl-lithium; and alkalinemetal alkoxides of lower (C₁-C₄) alcohols, such as lithium methoxide,potassium t-butoxide, potassium methoxide, and/or sodium methoxide.Other suitable basic compounds include carbonates and bicarbonates ofalkali metals or alkaline earth metals. Preferred classes of basiccatalysts include potassium carbonate, sodium carbonate, bariumcarbonate, or mixtures of these compounds having particle sizes that areless than about 100 microns, preferably less than about 50 microns.These preferred catalysts could be used in admixture with the moreconventional basic catalysts, described above. Potassium carbonateand/or potassium methoxide are also preferred catalysts. These catalystsare further disclosed in U.S. Pat. No. 4,517,360, to Volpenhein et al.,which is incorporated by reference.

Applicants have found that during the initial reaction phase it ispreferable that the initial reaction mixture be as homogeneous aspossible. A homogenous initial reaction mixture can be achieved byselection of appropriate reaction mixture ingredients that dissolve inthe presence of the selected solvent. Examples of suitable solvents areselected from the group consisting of dimethyl formamide, acetonitrile,acetone, and mixtures thereof. Dimethyl formamide is a particularlypreferred solvent.

If the preferred degree of homogeneity is not readily achieved upon theadmixing of the initial reaction mixture components, either by virtue ofthe ingredients or various other processing parameters selected, asufficient amount of agitation may be applied during the initialreaction phase to form an approximately homogeneous mixture or emulsion.Agitation should be applied for a period of time necessary to maintainhomogeneity throughout the duration of the initial reaction. Onceagitation has been applied for a period of time necessary to assurehomogeneity of the reactants throughout the reaction, furtherapplication of agitation may be continued, discontinued, or varied inforce.

As used herein the term, “a sufficient amount of agitation” is definedas the level of agitation necessary to ensure that reaction components(e.g., the initial reaction mixture) do not separate into discretephases for a period of time in excess of about 10 seconds, preferably inexcess of about 20 seconds, more preferably in excess of about 30seconds, more preferably in excess of about 45 seconds, most preferablyin excess of about 60 seconds, following discontinuation of theagitation. Preferably, agitation is applied during the reaction for aperiod of time sufficient to ensure that the degree of esterification ofthe highly esterified polyol polyester fatty acid is less than about50%, preferably less than about 40%, more preferably less than about30%, most preferably less than about 15%.

In one embodiment of the present invention a heterogeneous initialreaction mixture comprises sucrose, a highly esterified sucrose fattyacid with a degree of esterification of about 95%, a potassium carbonatecatalyst, and dimethyl formamide (DMF) as a solvent. Agitation isapplied by use of a rotating impeller. The degree of agitation necessaryto ensure a suitable degree of homogeneity throughout the reaction isquantified by a Weber Number in the range of from about 2000 to about20,000, operating for a period of time in the range of from about 10minutes to about 6 hours. In another embodiment the degree of agitationnecessary to ensure suitable homogeneity is quantified by a Weber Numberof about 10,000, applied for approximately 60 minutes. In yet anotherembodiment the agitation is quantified by a Weber Number of about 9,000applied for the entire duration of a 120-minute reaction time.

As used herein, any device capable of inducing motion in the fluidreaction mixtures over a range of viscosities, thus effecting adispersion of the components, is a suitable agitator for use in theprocesses of the present invention. Examples of suitable agitatorsinclude, impellors, paddles, kneaders, helical rotors, single sigmablade, double sigma blades, screw-type agitators, ribbon agitators, andmixtures thereof.

As used herein, the “Weber Number” is a dimensionless number intended toprovide a system independent measure of the agitation force applied to areaction mixture. The Weber Number is defined by Equation 1.$\begin{matrix}{\frac{\begin{matrix}{\left( {{Density}\quad{of}\quad{the}\quad{Continuous}\quad{Phase}} \right) \times} \\{\left( {{RPM}\quad{of}\quad{the}\quad{Impellor}} \right)^{2} \times \left( {{Diameter}\quad{of}\quad{the}\quad{Impellor}} \right)^{3}}\end{matrix}}{\begin{matrix}{{Interfacial}\quad{Tension}\quad{between}\quad{the}\quad{Continuous}\quad{and}} \\{{Discontinuous}\quad{Phases}}\end{matrix}}.} & {{Equation}\quad 1}\end{matrix}$ii) Catalyst Neutralization

Optionally, any catalyst remaining subsequent to the formation of theinitial reaction product may be neutralized with an acid. Applicantshave hereby found that neutralization of the remaining catalyst reducesthe risk of saponification and base catalyzed hydrolysis reactionsduring aqueous purification, both of which adversely impact the purityof the partially esterified polyol fatty acid compositions.

To effectively neutralize any residual catalyst, a sufficient amount ofan acid is added to the initial reaction product such that the molarratio of the acid to total catalyst is in the range of from about 0.01:1to about 1:1, preferably in the range of from about 0.1:1 to about0.8:1, more preferably in the range of from about 0.6:1 to about 0.8:1.Examples of acids suitable for use in neutralizing any residual basecatalyst include those acids selected from the group consisting ofhydrochloric, phosphoric, chromic, iodic, benzoic, hydrofluoric,sulfuric, sulfurous, acetic, formic, nitric, and mixtures thereof.

iv) Secondary Reaction Product

Optionally, a Secondary reaction product may be formed subsequent to theformation of the initial reaction product. The primary purpose forforming the secondary reaction product is to recover various initialreaction mixture components, such as solvent, that are no longerrequired for the remaining purification processes. Additionally, removalof the solvent by formation of the secondary reaction product reducesthe amount of solvent present in the final partially esterified polyolfatty acid polyester compositions.

The secondary reaction product is formed by reacting the secondaryreaction product at a pressure in the range of from about 0.01 mmHg toabout 760 mmHg, preferably in the range of from about 0.1 mmHg to about20 mmHg, more preferably in the range of from about 0.1 mmHg to about 10mmHg, most preferably in the rang of from about 0.1 mmHg to abut 5 mmHg,and for a period of time in the range of from about 30 minutes to about4 hours.

In one embodiment of the present invention the desired reaction pressuredictates the temperature at which the secondary reaction product isformed. In another embodiment of the invention the desired reactiontemperature dictates the reaction pressure to be employed. Preferablythe secondary reaction product is formed at the temperature-pressurecombination at which distillation of the solvent used in the initialreaction mixture occurs.

In yet another embodiment the solvent is dimethyl formamide. Preferredtemperature-pressure combinations for dimethyl formamide are selectedfrom the group consisting of about 0.1 mmHg and about negative 21° C.,about 1 mmHg and about 6° C., about 10 mmHg and about 41° C., about 100mmHg and about 91° C., and about 760 mmHg and about 153° C.

One of ordinary skill in the art will appreciate upon reading thedisclosure herein that the temperatures disclosed in the preferredtemperature-pressure combinations refer to the temperature of thereaction ingredients, not the temperature setting of the equipment usedto heat the reaction components. The ordinarily skilled artisan willalso appreciate that the temperatures are approximations based on thedistillation temperatures of the pure solvent and may vary slightlydepending on the degree of solvent purity.

In one embodiment of the present invention, the step of neutralizing anyremaining catalyst is performed subsequent to the formation of theinitial reaction product, but prior to the formation of a secondaryreaction product. In another embodiment the secondary reaction productis formed subsequent to the formation of the initial reaction product,though prior to the neutralization of remaining catalyst. In yet anotherembodiment, the remaining catalyst is neutralized with an acid withoutthe formation of a secondary reaction product. In yet another embodimentthe secondary reaction product is formed, while the remaining catalystis not neutralized.

v) Purification

(a) Solvent Free Aqueous Purification Processes

The reaction products of the present invention may be purified by anaqueous purification process, via application of a water washingsolution. Applicants have found that in order to obtain partiallyesterified polyol polyester compositions with the requisite degree ofpurity, the aqueous purification process should be free of any solventsthat would adversely affect the finished product purity requirement forthe composition's intended use (e.g., food grade purity). As any solventadded after formation of the initial reaction product must ultimately beremoved via a purification process, it is particularly preferred thatthe aqueous purification process be a solvent free purification process.

The water washing solution comprises from about 0.1% to about 5% of asalt and from about 95% to about 99.9% water. The water washing solutionis applied over a period of time in the range of from about 2 minutes toabout 30 minutes, preferably in the rang of from about 5-10 minutes. Theweight ratio of the water washing solution to the initial weight of thereaction product to be purified (e.g., initial reaction product;secondary reaction product; acid neutralized initial reaction product;or acid neutralized secondary reaction product) is in the range of fromabout 3:1 to about 30:1, preferably in the range of from about 5:1 toabout 20:1, more preferably in the range of from about 8:1 to about15:1. The temperature of the water washing solution is in the range offrom about 20° C. to about 100° C., and the temperature of the reactionproduct to be purified is in the range of from about 20° C. to about100° C. Preferably the temperature of the water washing solution is inthe range of from about 20° C. to about 60° C. when the majority of thefatty acid esters are unsaturated, and in the range of from about 40° C.to about 80° C. when the majority of the fatty acid esters aresaturated.

Examples of salts suitable for use in the present invention includesalts selected from the group consisting of calcium salts, magnesiumsalts, barium salts, sodium salts, potassium salts, cesium salts, andmixtures thereof. Preferred salts for use in the present inventioninclude salts selected from the group consisting of lithium chloride,lithium bromide, lithium iodide, lithium sulfate, calcium chloride,calcium bromide, calcium iodide, calcium sulfate, magnesium chloride,magnesium bromide, magnesium iodide, magnesium sulfate, barium chloride,barium bromide, barium iodide, barium sulfate, sodium chloride, sodiumbromide, sodium iodide, sodium sulfate, potassium chloride, potassiumbromide, potassium iodide, potassium sulfate, cesium chloride, cesiumbromide, cesium iodide, cesium sulfate, and mixtures thereof. Saltsselected from the group consisting of calcium chloride, calcium bromide,calcium iodide, calcium sulfate, and mixtures thereof are particularlypreferred.

Preferably, the water portion of the water washing solution is mixedwith the reaction product to be purified for a period of time in therange of from about 2 minutes to about 15 minutes prior to theintroduction of the salt. Subsequently, the salt is added to thewater/reaction product combination and mixed for an additional period oftime in the range of from about 2 minutes to about 15 minutes. Not to belimited by theory, Applicants believe that the salt facilitates theseparation of impurities and other unwanted reaction byproducts from thefinished product composition.

Following application of the water washing solution, impurities,unreacted components, and reaction byproducts are collected and removedfrom the washed reaction product. The washed reaction product separatesinto two discrete layers. The top layer contains the impurities,solvent, reaction byproducts, and unreacted reaction components to beremoved and discarded. The bottom layer contains the partiallyesterified polyol fatty acid polyester. Optionally, the top layer may becollected and processed to recover and/or recycle any desired reactioningredients and/or byproducts (e.g., polyol and solvent).

Separation into the discrete phases may be accomplished by allowing thewashed reaction products to gravity settle. Preferred methods for theseparation and isolation of impurities include centrifugation for aperiod of time in the range of from about 5 minutes to about 30 minutesat an applied force of from about 100G to about 15000G. Alternatively,when the majority (i.e., in excess of about 50%) of the fatty acidesters of the reaction product to be purified (e.g., initial reactionproduct; secondary reaction product; acid neutralized initial reactionproduct; or acid neutralized secondary reaction product) compriseunsaturated fatty acid esters, separation into discrete phases may beachieved via temperature reduction. The temperature separation step,wherein the temperature of the washed reaction product is decreased to atemperature below about 20° C., preferably below about 15° C., morepreferably below about 10° C., more preferably below about 5° C., mostpreferably at or below about 0° C., occurs after washing with a solventfree aqueous wash solution. As the temperature decreases, the washedreaction product separates into two discrete layers, an upper layercontaining impurities and a bottom layer comprising purified reactionproduct. The upper layer containing the impurities is collected andremoved. The bottom layer comprising purified, partially esterifiedpolyol fatty acid polyesters can be either collected for finalprocessing or subjected to additional purification processes.

The various techniques for the isolation and removal of impurities andunwanted reaction byproducts described herein may be used eitherindependently or in combination. In one embodiment of the presentinvention isolation of impurities occurs by centrifugation. In anotherembodiment, isolation is achieved by employing both centrifugation andtemperature reduction processes. In yet another embodiment, a productpurification cycle comprising the steps of washing the reaction productwith a solvent free water washing solution and then centrifuging thewashed reaction product to isolate impurities is repeated for a total often times. Subsequent to the tenth washing-centrifuging cycle, thetemperature of the washed reaction product is decreased to about 0°C. Asthe temperature approaches 0° C. the washed reaction product separatesinto two discrete layers. The top layer containing the impurities isisolated and removed, and the bottom layer comprising the purifiedreaction product is collected for final processing.

The purification process of washing the reaction product and separatingand collecting the partially esterified polyol polyester may optionallybe performed one or more additional times, depending on productcomposition at the end of the purification cycle and the desiredfinished product purity specification. Preferably the purification cycleis repeated in the range of from about 1 to about 20 times to achieveparticularly high degrees of purification.

In one embodiment of the present invention the water washingpurification steps are repeated in the range of from about 5 to about 15times. The quantity of water washing solution to be used in eachpurification cycle is calculated based on the initial weight of thereaction product to be purified (i.e., the weight of the reactionproduct prior to the first purification cycle). In each cycle the weightratio of the water washing solution to the initial weight of the washedreaction product to be purified (e.g., initial reaction product;secondary reaction product; acid neutralized initial reaction product;or acid neutralized secondary reaction product) is within the range offrom about 3:1 to about 30:1, preferably in the range of from about 5:1to about 20:1, more preferably in the range of from about 8:1 to about15:1.

The quantity of water washing solution utilized may be substantially thesame for each purification cycle, or alternatively may vary from cycleto cycle. Additionally, the quantity of salt utilized in the water washsolution may be substantially the same for each purification cycle, oralternatively may vary from cycle to cycle. Combinations of varyingamounts of water and salt within the water washing solution of variouspurification cycles are also contemplated.

In one embodiment, the quantity of salt utilized in the water washingsolutions of a purification cycle subsequent to the first purificationcycle is less than the quantity of salt utilized in the firstpurification cycle.

For each of the purification cycles the temperature of the water washingsolution is in the range of from about 20° C. to about 100° C., and thetemperature of the reaction product to be purified is in the range offrom about 20° C. to about 100° C.

Optionally, the weight ratio of water washing solution to reactionproduct to be purified may be recalculated after each purificationcycle, such that the weight ratio of the water washing solution to theweight of the reaction product to be purified in a given purificationcycle is in the range of from about 3:1 to about 30:1, preferably in therange of from about 5:1 to about 20:1, more 5 preferably in the range offrom about 5:1 to about 10:1.

When the majority (i.e., in excess of about 50%) of fatty acid esters ofthe reaction product to be purified (e.g., initial reaction product;secondary reaction product; acid neutralized initial reaction product;or acid neutralized secondary reaction product) comprise unsaturatedfatty acid esters, the last phase of the purification cycle mayoptionally contain a freezing step. The freezing step occurs after thefinal aqueous wash and centrifugation.

Following the final wash with the water washing solution, the top layercontaining the impurities and other unwanted reaction byproducts iscollected and removed. The temperature of the bottom layer comprisingthe purified reaction product is then lowered to a temperature at orbelow about 0°C. As the temperature decreases, the bottom layerseparates into two discrete layers, an upper layer which containsimpurities, and a bottom layer comprising further purified reactionproduct. The upper layer containing the impurities is collected anddiscarded, leaving a purified reaction product comprising partiallyesterified polyol fatty acid polyesters.

(b) Alcohol Purification Processes

The reaction products of the present invention may optionally bepurified by an alcohol purification process, via application of analcohol washing solution. Applicants have found that in order to obtainpartially esterified polyol polyester compositions with the requisitedegree of purity, the alcohol purification process should be free of anyadditional solvents that would adversely affect the finished productpurity requirement for the composition's intended use (e.g., food gradepurity). As any solvent added after formation of the inital reactionproduct must ultimately be removed via a purification process, it ispreferred that the alcohol washing solution contain no additionalingredients that would not be substantially removed, preferablycompletely removed, by the alcohol wash process. Particularly preferredembodiments of the resent invention are those where the alcohol washsolution comprises no ingredients, other than perhaps impurities at alevel that would not adversely impact finished product purity, beyondthe alcohol.

The alcohol washing solution comprises alcohols with a carbon chainlength in the range of from about 2 atoms to about 5 atoms. The alcoholwashing solution is applied over a period of time in the range of fromabout 2 minutes to about 30 minutes, preferably in the rang of fromabout 5-10 minutes. The weight ratio of the alcohol washing solution tothe initial weight of the reaction product to be purified (e.g., initialreaction product; secondary reaction product; acid neutralized initialreaction product; or acid neutralized secondary reaction product) is inthe range of from about 3:1 to about 30:1, preferably in the range offrom about 5:1 to about 20:1, more preferably in the range of from about5:1 to about 10:1.

The temperature of the alcohol washing solution is in the range of fromabout 20° C. to about 100° C., and the temperature of the reactionproduct to be purified is in the range of from about 20° C. to about100° C. Preferably the temperature of the alcohol washing solution is inthe range of from about 20° C. to about 60° C. when the majority of thefatty acid esters are unsaturated, and in the range of from about 40° C.to about 80° C. when the majority of the fatty acid esters aresaturated.

Examples of alcohols suitable for use in the present invention includeethanol, n-propanol, n-butanol, n-pentanol, branched and non-terminalforms of C₂-C₅ alcohols, and mixtures thereof. Preferred alcohols areselected from the group consisting of ethanol, n-propanol, n-butanol,n-pentanol, and mixtures thereof.

Following application of the alcohol washing solution, impurities,unreacted components, and reaction byproducts are collected and removedfrom the washed reaction product. The washed reaction product separatesinto two discrete layers. The bottom layer contains the impurities,solvent, reaction byproducts, and unreacted reaction components to beremoved and discarded. The top layer contains the partially esterifiedpolyol fatty acid polyester. Optionally, the bottom layer may becollected and processed to recover and/or recycle any desired reactioningredients and/or byproducts (e.g., polyol and solvent).

Separation into the discrete phases may be accomplished by allowing theimpurities and byproducts to gravity settle. Preferred methods for theseparation and isolation of impurities include centrifugation for aperiod of time in the range of from about 5 minutes to about 30 minutesat an applied force of from about 100G to about 15000G, preferably inthe range of from about 2000G to about 10,000G.

The purification cycle of washing the reaction product with alcohol andseparating and collecting the partially esterified polyol polyester mayoptionally be performed one or more additional times, depending on theproduct composition following the purification cycle and the desireddegree of purity in the finished product. Preferably the purificationprocess is repeated in the range of from about 1 to about 20 times toachieve particularly high degrees of purification.

In one embodiment of the present invention the alcohol washingpurification steps are repeated in the range of from about 5 to about 15times. The quantity of alcohol washing solution to be used in eachpurification cycle is calculated based on the initial weight of thereaction product to be purified (i.e., the weight of the reactionproduct prior to the first purification cycle). In each cycle the weightratio of the alcohol washing solution to the initial weight of thewashed reaction product to be purified (e.g., initial reaction product;secondary reaction product; acid neutralized initial reaction product;or acid neutralized secondary reaction product) is within the range offrom about 3:1 to about 30:1, preferably in the range of from about 5:1to about 20:1, more preferably in the range of from about 8:1 to about15:1. The quantity of alcohol washing solution utilized may besubstantially the same for each purification cycle, or alternatively mayvary from cycle to cycle.

For each of the purification cycles the temperature of the alcoholwashing solution is in the range of from about 20° C. to about 100° C.,and the temperature of the reaction product to be purified is in therange of from about 20° C. to about 100° C.

Optionally, the weight ratio of alcohol washing solution to reactionproduct to be purified may be recalculated after each purificationcycle, such that the weight ratio of the alcohol washing solution to theweight of the reaction product to be purified in a given purificationcycle is in the range of from about 3:1 to about 30:1, preferably in therange of from about 5:1 to about 20:1, more preferably in the range offrom about 5:1 to about 10:1.

C. Composition of Purified, Partially-Esterified Polyol Fatty AcidPolyesters

The purified, partially esterified polyol polyester fatty acidcompositions of the present invention generally comprise a partiallyesterified polyol polyester with a degree of esterification of less thanabout 50%, preferably less than about 40%, more preferably less thanabout 30%, more preferably less than about 15%. Additionally, thepurified, partially esterified polyol polyester fatty acid compositionscomprise less than about 5% polyol, preferably less than about 3.5%polyol, more preferably less than about 2% polyol, more preferably lessthan about 1.1% polyol; less than about 5 ppm (parts per million) ofresidual solvent, preferably less than about 4 ppm of residual solvent,most preferably less than about 3 ppm of residual solvent; and less thanabout 700 ppm of lower alkyl esters, preferably less than about 650 ppmof lower alkyl esters, more preferably less than about 500 ppm of loweralkyl esters, more preferably less than about 200 ppm of lower alkylesters, more preferably less than about 100 ppm of lower alkyl esters,most preferably less than about 50 ppm of lower alkyl esters of loweralkyl esters. Moreover, the purified, partially esterified polyolpolyester compositions comprise less than about 5% of a soap and freefatty acid mixture, preferably less than about 4.5% of a soap and freefatty acid mixture, more preferably less than about 4% of a soap andfree fatty acid mixture, more preferably less than about 3.5% of a soapand free fatty acid mixture, most preferably less than about 3.3% of asoap and free fatty acid mixture.

The purified, partially esterified polyol polyesters also comprise lessthan about 3% ash, preferably less than about 2% ash, more preferablyless than about 1.7% ash. As used herein, the term “ash” refers tosulfated ash. The amount of sulfated ash in the present invention iscalculated by weighing 5 grams of a sample into a platinum dish. Then 5mL of 10% Sulfuric acid (H₂SO₄) is added to the sample, and the mixtureis heated until carbonized. The carbonized ash is then baked in a mufflefurnace at 550° C. until ashed. An additional aliquot of 2-3 mL of 10%Sulfuric Acid is added, and the mixture is again heated untilcarbonized. Again the mixture is baked at 550° C. until ashed. Thisprocess is repeated until the ash maintains a constant weight. Thepercentage of sulfated ash is calculated by dividing the weight of theremaining ash by the sample weight.

Furthermore, the purified polyester compositions of the presentinvention have an acid value of less than about 6, preferably an acidvalue less than about 4, more preferably an acid value less than about3, most preferably an acid value less than about 2.

Not to be limited by theory, Applicants believe residual levels of loweralkyl ester impurities may be attributed to those amounts that exist asan impurity within the highly esterified polyol polyester fatty acidsprior to inclusion in the initial reaction mixture. Soap and free fattyacid mixtures are believed to be byproducts resulting from polyoldegradation and catalyst neutralization reactions. Ash is also believedto be a byproduct of various degradation and purification processeswithin the synthesis of the purified, partially esterified polyolpolyester compositions.

D. Examples

The following are non-limiting examples of partially esterified polyolpolyester and purified, partially esterified polyol polyestercompositions and methods of making the same, used in accordance with thepresent invention. The following examples are provided to illustrate theinvention and are not intended to limit the spirit or scope thereof inany manner.

EXAMPLE 1

In the present example, an initial reaction mixture comprises 75 g(0.0314 moles) of sucrose polyester, based on oleic fatty acids, with adegree of esterification of 96%; 161 g (0.471 moles) of sucrose; 7 g(0.0507 moles) of potassium carbonate; and 530 g of dimethyl formamidesolvent. Prior to use in the initial reaction mixture the sucrose andcatalyst were dried in a vacuum oven for 12 hours. An initial reactionproduct is formed by reacting the initial reaction mixture at 100° C.for 300 minutes in a two-piece, baffled glass reactor. The initialreaction mixture is reacted in the presence of agitation to ensure evenheat distribution of the reaction components.

A sample of the initial reaction product is analyzed by super fluidchromatography (SFC) and found to have the composition shown in Table1A, wherein SE_(X) indicates a Sucrose Ester with X esterified hydroxylgroups. Suitable super fluid chromatography analytical methods aredescribed in co-pending application U.S. patent Ser. No. 09/646,293,filed Sep. 15, 2000 to Trout et al., entitled Improved Processes forSynthesis and Purification of Nondigestible Fats.

TABLE 1A Soap Sucrose SE₁ SE₂ SE₃ SE₄ SE₅ SE₆ SE₇ SE₈ 1.0 45.4 38.1 13.42.2 0.0 0.0 0.0 0.0 0.0

EXAMPLE 2

In the present example, an initial reaction mixture comprises 75 g(0.0314 moles) of sucrose polyester with a degree of esterification of96%; 161 g (0.471 moles) of sucrose; 5 g (0.036 moles) of potassiumcarbonate; and 540 g of dimethyl formamide solvent. An initial reactionproduct is formed by reacting the initial reaction mixture at 100° C.for 300 minutes in a two-piece, baffled glass reactor. The initialreaction mixture is reacted in the presence of agitation to ensure evenheat distribution of the reaction components.

A sample of the initial reaction product is analyzed by Super FluidChromatography (SFC) and found to have the composition shown in Table2A.

TABLE 2A Soap Sucrose SE₁ SE₂ SE₃ SE₄ SE₅ SE₆ SE₇ SE₈ 1.0 45.2 38.2 13.52.2 0.0 0.0 0.0 0.0 0.0

The initial reaction product weighs 781 g. 736 g of the initial reactionproduct is then evaporated in a round bottom flask heated in a 60° C.water bath, under a pressure of 0.8 mmHg, for 120 minutes to form asecondary reaction product. The secondary reaction product weighs 270 g.

A sample of the secondary reaction product is analyzed by SupercriticalFluid Chromatography (SFC) and found to have the composition shown inTable 2B.

TABLE 2B Soap Sucrose SE₁ SE₂ SE₃ SE₄ SE₅ SE₆ SE₇ SE₈ 1.1 44.6 36.9 14.13.1 0.0 0.0 0.0 0.0 0.0

EXAMPLE 3

In the present example, an initial reaction mixture comprises 75 g(0.0314 moles) of sucrose polyester with a degree of esterification of96%; 161 g (0.471 moles) of sucrose; 5 g (0.036 moles) of potassiumcarbonate; and 540 g of dimethyl formamide solvent. An initial reactionproduct is formed by reacting the initial reaction mixture in thepresence of agitation at 100° C. for 300 minutes in a two-piece, baffledglass reactor.

A sample of the initial reaction product is analyzed by Super FluidChromatography (SFC) and found to have the composition shown in Table3A.

TABLE 3A Soap Sucrose SE₁ SE₂ SE₃ SE₄ SE₅ SE₆ SE₇ SE₈ 1.1 45.4 38.0 13.42.2 0.0 0.0 0.0 0.0 0.0

The primary reaction product weighs 781 g and is treated with 2.5 g of36.5% hydrochloric acid (0.025 moles) to neutralize the remainingcatalyst. The initial reaction product is then evaporated in a roundbottom flask heated in a 60° C. water bath, under a pressure of 0.6mmHg, for 120 minutes to form a secondary reaction product. Thesecondary reaction product weighs 281 g.

210 g of the acid neutralized secondary reaction product is mixed in astainless steel mixing vessel with 2100 g of 30° C. water for 5 minutes.The temperature is held constant. 5.25 g of calcium chloride is added tothe system and mixed for an additional 5 minutes. The resulting mixtureis centrifuged at 5000G for 10 minutes. The centrifuged mixture splitsinto two discrete layers. The top layer is discarded and the bottomlayer is recovered.

The entire bottom layer is collected and re-washed with 2100 g of 30° C.water for 5 minutes, holding the temperature constant. 5.25 g of calciumchloride are added and the system is mixed for an additional 5 minutes.The mixture is centrifuged at 5000G for 10 minutes and the bottom layeris again recovered for further washing. The recovery and rewashing ofthe bottom layer is repeated for a total of three additional times, fora total of 5 washes with 5.25 g of calcium chloride.

After the fifth wash, the bottom layer is collected and re-washed in astainless steel mixing vessel with 2100 g of 30° C. water for 5 minutes,holding the temperature constant. 3.15 g of calcium chloride are added,and the system is mixed for an additional 5 minutes. The mixture iscentrifuged at 5000G for 10 minutes and the bottom layer is againrecovered for further washing. The process of collecting the bottomlayer, rewashing in the presence of 3.15 g of calcium chloride, andcentrifuging is repeated for a total of three additional times.

After the ninth total wash, the bottom layer is recovered and put into afreezer at −5° C. The bottom layer splits into two discrete phases. Thetop layer is discarded and the bottom layer is recovered and dried in avacuum oven at 45° C. and 1 mmHg for 12 hours to produce a purified,partially esterified polyol fatty acid polyester composition.

The final product composition is analyzed by SFC and shown in Table 3B.

TABLE 3B Sulfated Acid DMF Soap/FFA Sucrose Ash Value SE₁ SE₂ SE₃ SE₄SE₅ SE₆ SE₇ SE₈ 1 ppm 2.4 0.0 1.8% 2.0 50.1 28.3 16.1 3.0 0.0 0.0 0.00.0

EXAMPLE 4

In the present example, an initial reaction mixture comprises 77.5 g(0.0322 moles) of sucrose polyester having a degree of esterification of96%; 200 g (0.585 moles) of sucrose; 2.0 g (0.0145 moles) of potassiumcarbonate; and 507 g of dimethyl formamide solvent. Prior to use in theinitial reaction mixture the sucrose and catalyst were dried in a vacuumoven for 12 hours. An initial reaction product is formed by reacting theinitial reaction mixture, in the presence of agitation, at 110° C. for300 minutes in a two-piece, baffled glass reactor.

A sample of the initial reaction product is analyzed by Super FluidChromatography (SFC) and found to have the composition of Table 4A.

TABLE 4A Soap Sucrose SE₁ SE₂ SE₃ SE₄ SE₅ SE₆ SE₇ SE₈ 1.0 53.0 31.5 12.12.4 0.0 0.0 0.0 0.0 0.0

The initial reaction product weighs 751 g and is treated with 1.45 g of36.5% hydrochloric acid (0.0141 moles) to neutralize the remainingcatalyst. The mixture is then evaporated in a round bottom flask heatedin a 60° C. water bath, under a pressure of 0.5 mmHg, for 120 minutes toform a secondary reaction product. The secondary reaction product weighs339 g.

210 g of the secondary reaction product is mixed in a stainless steelmixing vessel with 2100 g of 30° C. water for 5 minutes. The temperatureis held constant. 5.25 g of calcium chloride is added to the system andmixed for an additional 5 minutes. The resulting mixture is centrifugedat 5000G for 10 minutes. The centrifuged mixture splits into twodiscrete layers. The top layer is discarded and the bottom layer isrecovered.

The entire bottom layer is collected and re-washed with 2100 g of 60° C.water for 5 minutes, holding the temperature constant. 5.25 g of calciumchloride are added and the system is mixed for an additional 5 minutes.The mixture is centrifuged at 5000G for 10 minutes and the bottom layeris again recovered for further washing. The recovery and rewashing ofthe bottom layer is repeated for a total of three additional times, fora total of 5 washes with 5.25 g of calcium chloride.

After the fifth wash, the bottom layer is collected and re-washed in astainless steel mixing vessel with 2100 g of 60° C. water for 5 minutes,holding the temperature constant. 3.15 g of calcium chloride are added,and the system is mixed for an additional 5 minutes. The mixture iscentrifuged at 5000G for 10 minutes and the bottom layer is againrecovered for further washing. The process of collecting the bottomlayer, rewashing in the presence of 3.15 g of calcium chloride, andcentrifuging is repeated for a total of three additional times.

After the ninth total wash, the bottom layer is recovered and put into afreezer at −5° C. The bottom layer splits into two discrete phases. Thetop layer is discarded and the bottom layer is recovered and dried in avacuum oven at 45° C. and 1 mmHg for 12 hours to produce a purified,partially esterified polyol fatty acid polyester composition.

The final product composition is analyzed by SFC and shown in Table 4B.

TABLE 4B Sulfated Acid DMF Soap/FFA Sucrose Ash Value SE₁ SE₂ SE₃ SE₄SE₅ SE₆ SE₇ SE₈ 0.6 ppm 2.0 0.0 1.7% 2.7 61.2 29.2 7.6 0.0 0.0 0.0 0.00.0

Having now described several embodiments of the present invention itshould be clear to those skilled in the art that the forgoing isillustrative only and not limiting, having been presented only by way ofexemplification. Numerous other embodiments and modifications arecontemplated as falling within the scope of the present invention asdefined by the appended claims thereto.

1. A process for the preparation of a purified partially esterifiedpolyol fatty acid polyester composition comprising the steps of: a)forming an initial reaction mixture, said initial reaction mixturecomprising: i) a polyol portion; ii) a highly esterified polyol fattyacid polyester; iii) a solvent selected from the group consisting ofdimethyl formamide, acetonitrile, acetone, and mixtures thereof; and iv)a catalyst, wherein the molar ratio of said polyol portion to saidhighly esterified polyol polyester is in the range of from about 0.1:1to about 3:1, wherein the molar ratio of said catalyst to said highlyesterified polyol polyester is in the range of from about 0.1:1 to about40:1, and wherein the weight ratio of said solvent to the combined,weight of said polyol portion, said highly esterified polyol polyester,and said catalyst is in the range of from about 1:1 to about 20:1;forming as initial reaction product by reacting said initial reactionmixture in an inert atmosphere, in the presence of a sufficient amountof agitation, for a period of time in the range of from about 30 minutesto about 6 hours, and at a temperature in the range of from about 80° C.to about 140° C.; c) optionally drying said initial reaction product;wherein in Step (b) agitation is applied at a Weber Number in the rangeof from about 5000 to about 15000, and for a period of time in the rangeof from about 30 minutes to about 6 hours.
 2. The process of claim 1wherein said polyol portion is sucrose, said highly esterified polyolpolyester is highly esterified sucrose fatty acid polyester with adegree of esterification in excess of about 80%, and wherein saidcatalyst is selected from the group consisting of sodium, lithium,potassium, sodium-lithium alloys, sodium-potassium alloys, sodiumhydride, lithium hydride, potassium hydride, butyl-lithium, lithiummethoxide, potassium t-butoxide, potassium methoxide, sodium methoxide,potassium carbonate, sodium carbonate, barium carbonate, and mixturesthereof.
 3. The process of claim 2 wherein said highly esterified polyolpolyester is highly esterified sucrose fatty acid polyester with adegree of esterification in excess of about 95%, said catalyst isselected from the group consisting of potassium carbonate, sodiumcarbonate, barium carbonate, and mixtures thereof; and wherein saidsolvent is dimethyl formamide.
 4. A process for the preparation of apurified partially esterified polyol fatty acid polyester compositioncomprising the steps of: a) forming an initial reaction mixture, saidinitial reaction mixture comprising: i) a polyol portion; ii) a highlyesterified polyol fatty acid polyester; iii) a solvent; and, iv) acatalyst, wherein the molar ratio of said polyol portion to said highlyesterified polyol polyester is in the range of from about 0.1:1 to about3:1, wherein the molar ratio of said catalyst to said highly esterifiedpolyol polyester is in the range of from about 0.1:1 to about 40:1, andwherein the weight ratio of said solvent to the combined weight of saidpolyol portion, said highly esterified polyol polyester, and saidcatalyst is in the range of from about 1:1 to about 20:1; b) forming aninitial reaction product by reacting said initial reaction mixture in aninert atmosphere, in the presence of a sufficient amount of agitation,for a period of time in the range of from about 30 minutes to about 6hours, and at a temperature in the range of from about 80° C. to about140° C.; c) adding an acid to the initial reaction product to neutralizeany remaining catalyst, wherein the molar ratio of said acid to saidcatalyst is in the range of from about 0.01:1 to about 1:1; d) forming asecondary reaction product by reacting said initial reaction product ata temperature-pressure combination at which distillation of said solventoccurs, wherein the pressure is in the range of from about 0.01 mmHg toabout 760 mmHg, for a period of time in the range of from about 30minutes to about 4 hours; e) forming a purified reaction product bywashing said secondary reaction product with a solvent free waterwashing solution, said solvent free water washing solution comprising:i) from about 0.1% to about 5% of a salt; and ii) from about 95% toabout 99.9% water; wherein the weight ratio of said water washingsolution to said secondary reaction product is in the range of fromabout 3:1 to about 30:1, and wherein the temperature of said secondaryreaction product and said water wash solution are in the range of fromabout 20° C. to about 100° C., wherein said wash time is in the range offrom about 5 minutes to about 30 minutes; f) isolating and removingimpurities from said purified reaction product; g) optionally repeatingsteps (e) and (f) for a number of times in the range of from about 1 toabout 20; and, h) optionally drying said purification reaction product;wherein in Step (b) agitation is applied at a Weber Number in the rangeof from about 5000 to about 15000, and for a period of time in the rangeof from about 30 minutes to about 6 hours.
 5. The process of claim 4wherein said polyol portion is sucrose, said highly esterified polyolpolyester is highly esterified sucrose fatty acid polyester with adegree of esterification in excess of about 80%.
 6. The process of claim5 wherein said highly esterified polyol polyester is highly esterifiedsucrose fatty acid polyester with a degree of esterification in excessof about 90%.
 7. The process of claim 6 wherein said highly esterifiedpolyol polyester is highly esterified sucrose fatty acid polyester witha degree of esterification in excess of about 95%.
 8. The process ofclaim 4 wherein said solvent is selected from the group consisting ofdimethyl formamide, acetonitrile, acetone, and mixtures thereof.
 9. Theprocess of claim 8 wherein said solvent is dimethyl formamide.
 10. Theprocess of claim 4 wherein said catalyst is selected from the groupconsisting of alkali metals, alloys of two or more alkali metals, alkalimetal hydrides, alkali metal lower (C1-C4) alkyls, alkaline metalalkoxides of lower (C₁-C₄) alcohols, carbonates of alkali metals,carbonates of alkaline earth metals, bicarbonates of alkali metals,bicarbonates of alkaline earth metals, and mixtures thereof.
 11. Theprocess of claim 10 wherein said catalyst is selected from the groupconsisting of sodium hydride, lithium hydride, potassium hydride,lithium methoxide, potassium methoxide, sodium methoxide, potassiumcarbonate, sodium carbonate, barium carbonate, and mixtures thereof. 12.The process of claim 11 wherein said catalyst is potassium carbonate.13. The process of claim 4 wherein said polyol portion comprises a blendof at least two different polyols.
 14. The process of claim 13 whereinsaid polyol portion comprises sucrose and at least one additional polyolother than sucrose.
 15. The process of claim 13 wherein said solvent isdimethyl formamide, wherein said catalyst is potassium carbonate, 7wherein said highly esterified polyol polyester is highly esterifiedsucrose fatty acid polyester with a degree of esterification in excessof about 95%, and wherein in Step (f), isolation of said impuritiesoccurs by centrifuging said purified reaction product for a period oftime in the range of from about 5 minutes to about 30 minutes, at anapplied force in the range of from about 100G to about 20000G.
 16. Theprocess of claim 4 wherein said highly esterified polyol polyestercomprises at least two different highly esterified polyol polyesters.17. The process of claim 16 wherein said highly esterified polyolpolyester comprises a highly esterified sucrose polyester and at leastone additional highly esterified polyol polyester.
 18. The process ofclaim 17 wherein said polyol portion comprises sucrose and at least oneadditional polyol other than sucrose.
 19. The process of claim 4 whereinin Step (f) isolation of said impurities occurs by a method selectedfrom the group consisting of gravity settling, centrifugation,temperature reduction, and mixtures thereof.
 20. The process of claim 19wherein in Step (f), isolation of said impurities occurs by centrifugingsaid purified reaction product for a period of time in the range of fromabout 5 minutes to about 30 minutes, at an applied force in the range offrom about 100G to about 20000G.
 21. The process of claim 20 whereinisolation of said impurities occurs by centrifuging said purifiedreaction product for a period of time in the range of from about 5minutes to about 15 minutes, at an applied force in the range of fromabout 2500G to about 10000G.
 22. The process of claim 19 wherein saidpurified reaction product comprises polyol fatty acid polyesters havingin excess of about 50% unsaturated fatty acid esters, and wherein inStep (f) isolation of said impurities occurs by centrifuging saidpurified reaction product for a period of time in the range of fromabout 5 minutes to about 30 minutes, at an applied force in the range offrom about 100G to about 20000G.
 23. The process of claim 22 whereinisolation of said impurities additionally comprises the step of reducingthe temperature of said purified reaction product to a temperature lessthan about 10C and removing said impurities.
 24. The process of claim 20wherein the step (g), step (e) and step (f) are repeated for a number oftimes in the range of from about 1 to about 20 times.
 25. The process ofclaim 24 wherein following step (g), said impurities are furtherisolated by process comprising the steps of reducing the temperature ofsaid purified reaction product to a temperature less than about 10C andremoving said impurities after the formation of a discrete impuritieslayer.
 26. A process for the preparation of a purified partiallyesterified polyol fatty acid polyester composition comprising the stepsof: a) forming an initial composition comprising the steps of: i) apolyol portion; ii) a highly esterified polyol fatty acid polyester witha degree of esterification in excess of about 80%; iii) a solventselected from the group consisting of dimethyl formamide, acetonitrile,acetone, and mixtures thereof; and, iv) a catalyst, wherein the molarratio of said polyol portion to said highly esterified polyol polyesteris in the range of from about 0.1:1 to about 3:1, wherein the molarratio of said catalyst to said highly esterified polyol polyester is inthe range of from about 0.1:1 to about 40:1, and wherein the weightratio of said solvent to the combined weight of said polyol portion,said highly esterified polyol polyester, and said catalyst is in therange of from about 1:1 to about 20:1; b) forming an initial reactionproduct by reacting said initial reaction mixture in an inertatmosphere, in the presence of a sufficient amount of agitation, for aperiod of time in the range of from about 30 minutes to about 6 hours,and at a temperature in the range of from about 80° C. to about 140° C.;c) adding an acid to the inital reaction product to neutralize anyremaining catalyst, wherein the molar ratio of said acid to saidcatalyst is in the range of from about 0.01:1 to about 1:1; d) forming asecondary reaction product by reacting said inital reaction product at atemperature-pressure combination at which distillation of said solventoccurs, wherein the pressure is in the range of from about 0.1 mmHg toabout 760 mmHg, for a period of time in the range of from about 30minutes to about 4 hours; e) forming a purified reaction product bywashing said secondary reaction product with an alcohol washingsolution, said alcohol washing solution comprises an alcohol selectedfrom the group consisting of alcohols with a carbon chain length in therange of from about 2 atoms to about 5 atoms, wherein the weight ratioof said alcohol washing solution to said secondary reaction product isin the range of from about 3:1 to about 30:1, and wherein thetemperature of said secondary reaction product and said alcohol washsolution are in the range of from about 20° C. to about 100° C., whereinsaid wash time is in the range of from about 5 minutes to about 30minutes; f) isolating and removing impurities from said purifiedreaction product; g) optionally repeating steps (e) and (f) for a numberof times in the range of from about 1 to about 20; h) optionally dryingsaid purification reaction product.
 27. The process of claim 26 whereinin step (b) said inert atmosphere is selected from the group consistingof nitrogen, argon, helium, and combinations thereof.
 28. The process ofclaim 26 wherein said polyol portion is sucrose.
 29. The process ofclaim 28 wherein said highly esterified polyol polyester is highlyesterified sucrose fatty acid polyester with a degree of esterificationin excess of about 90%.
 30. The process of claim 29 wherein said highlyesterified polyol polyester is highly esterified sucrose fatty acidpolyester with a degree of esterification in excess of about 95%. 31.The process of claim 26 wherein said solvent is dimethyl formamide. 32.The process of claim 26 wherein said catalyst is selected from the groupconsisting of alkali metals, alloys of two or more alkali metals, alkalimetal hydrides, alkali metal lower (C1-C4) alkyls, alkaline metalalkoxides of lower (C₁-C₄) alcohols, carbonates of alkali metals,carbonates of alkaline earth metals, bicarbonates of alkali metals,bicarbonates of alkaline earth metals, and mixtures thereof.
 33. Theprocess of claim 32 wherein said catalyst is selected from the groupconsisting of sodium hydride, lithium hydride, potassium hydride,lithium methoxide, potassium methoxide, sodium methoxide, potassiumcarbonate, sodium carbonate, barium carbonate, and mixtures thereof. 34.The process of claim 33 wherein said catalyst is potassium carbonate.35. The process of claim 26 wherein in Step (b) agitation is applied ata Weber Number in the range of from about 5000 to about 15000, and for aperiod of time in the range of from about 30 minutes to about 6 hours.36. The process of claim 26 wherein in Step (f) isolation of saidimpurities occurs by a method selected from the group consisting ofgravity settling, centrifugation, temperature reduction, and mixturesthereof.
 37. The process of claim 36 wherein in Step (f), isolation ofsaid impurities occurs by centrifuging said purified reaction productfor a period of time in the range of from about 5 minutes to about 30minutes, at an applied force in the range of from about 100G to about20000G.
 38. The process of claim 37 wherein isolation of said impuritiesoccurs by centrifuging said purified reaction product for a period oftime in the range of from about 5 minutes to about 15 minutes, at anapplied force in the range of from about 2500G to about 10000G.
 39. Theprocess of claim 36 wherein said purified reaction product comprisespolyol fatty acid polyesters having in excess of about 50% unsaturatedfatty acid esters, and wherein in Step (f) isolation of said impuritiesoccurs by centrifuging said purified reaction product for a period oftime in the range of from about 5 minutes to about 30 minutes, at anapplied force in the range of from about 100G to about 20000G.
 40. Theprocess of claim 37 wherein in step (g), step (e) and step (f) arerepeated for a number of times in the range of from about 1 to about 20times.
 41. The process of claim 1 wherein the highly esterified polyolpolyester has a degree of esterification of at least about 70%.